Internal-combustion engine.



Patented Apr. 14, 1914.

2 SHEETS-8113B)? l.

H. LEMP.

INTERNAL COMBUSTION ENGINE. APPLICATION I-ILED JUNE 24, 1911.

witn sise$ Inventor; Hr'manrl Lempq H. LEMP.

INTERNAL COMBUSTION ENGINE.

APPLIUATION FILED JUNE 24, 1911.

Patenied- Apr. 14 1914 LOQEAQO Fig.5.

Inventor? Hermann Lem Witnesses.

' support the crank-shaft 2.

-33 of Fig. 1.

' pairs being .inder is located a close fitting p ys ASSIGNOR TO GENERALELECTRIC OF NEW YORK.

INTERNAL-COMBUSTION ENGINE.

To all whom it may; concern: 4

Be it known that I, HERMANN LEMP, a citizen of the United States,residing at Lynn, county of Essex, State of Massaohusetts, have inventedcertain new and useful Improvements in Internal-Combustion.Engines, ofwhich the following. is a specification. a

-The present invention relates to internal combustion engines of thetype utilizinga relatively heavy oil and in which the temperature of thefluid within the cylinder due to compression, is utilized to ignite thecharge, and has for its object to improve their construction, particularreference being made to the arrangement of working and pump pistons andcylinders, to the means for scavenging the cylinders, to the arrangementfor admitting .fuel and com-' pressedair to the cylinders, and to theelimination of puppet and similar valves.

In the accompanying drawing which illustrates one of theembodiments ofmy invention, Figure 1 is a view partly in sect-ionand partly in sideelevation of a multi-cylinder engine; Fig. 2 is a sectional view of thesame at right angles to Fig. 1; and Fig. 3 is a plan view partly insection on the line 1 indicates the base of the engine which is providedwith side portions that inclose and To the top of the base are securedanumber of working cylinders 3 arranged in pairs, two of suchillustrated, and also anumber of pump cylinders 4 axially alined withthe working cylinders.

Each ump cylinder is much larger in diameter t an the working cylinderso as to insure a supplyof fresh air largely in excess of that displacedby the working piston. I find it desirable in some cases to make thepump cylinders fifty per cent. larger than the working cylinders. This alimitation of my invention. In each cylpiston, the working piston 6 andthe pump piston 7 being connected by a rod 8. The pistons for each pumand working cylinder are cast. in one cult, and thepump piston inaddition to operating as such serves as a guide for the working piston.

The working cylinder 3 is provided with ports 9 thatadmit a large amountof pure Specification of Letters Yatent. Application filed June 24,1911.

'lbs. per square inch. figure is given as an illustration and not as Itshould further Patented Apr. id, 19143:. Serial No. 635,118.

air for scavenging purposes. ever, provided with exhaust ports for theburned products of combustion as will appear later.

The pump cylinder 4 is provided with air admltting ports 10 located inthe cylinder near the upper end of the piston stroke and controlled bythe piston 7. The lower end of the cylindcrhas an outlet 11 thatdischarges into the receiver '12. This receiver 15 common to the pumpcylinders 4 and 13, air from the latter being conveyed to it by theconduit 14. In other words, the two pumps supply air in multiple to thereceiver and to the working cylinder 3. This receiver must have, for thebest operation, a capacity substantially equal to the displacement ofboth pump pistons to avoid losses due to compression. The receiver 12 isconnected to an annular chamber 15 that surrounds the cylinder 3 andfrom which the air ports 9 enter the cylinder proper and are controlledby the piston 6.

The working cylinder 17 that is paired with working cylinder 3 isprovided with exhaust ports 18 that discharge into a cylindrical chamber19, the latter communicating with the exhaust pipe. The exhaust portsare cont-rolled by the working piston 21. These ports are common to bothworking cylinders, said cylinders being connect ed at the top y aconduit 22. Fuel in the nature of a rather heavy oil is forced into theconduit 22 by air under a pressure which materially exceeds that causedby the compression of the Working pistons. For example the workingpistons may compress the pure air in the cylinders after the burnedproducts of combustion have been forced out to a pressure of 500 lbs.per square inch. On the other hand the oil and air may be forced intothe conduit 22 and into the working cylinders under a pressure of say1000 It is not, how- The pistons are connected by a wrist pin 23 whichin turn is connected by the connecting rod 24.- to the main crankshaft2. From this construction it follows that the movements of the pistonsare simultaneous. be noted that the pistons for the working and pumpcylinders are so arranged that as one piston moves toward its closedend, the other piston moves toward its open end; or in other words, asone piston compresses or expels the contents of, its

' cylinder the other piston is drawing air or is provided.

gas into its cylinder. It is on account of this latter arrangement thatthe receiver 12 with the cylinder having no exhaust ports it followsthat the pure air from the pumps must also pass serially through thecylinders and conduit 22 to the exhaust ports 18. It is further to benoted that the two pumps discharge in multiple into said air ports. Owinto the arrangement of the parts above descri ed and to the fact that thedisplacement of the pump pistons is greatly in excess of that of theworking pistons, the pure air as it rumes through the ports, cylindersand connecting conduit drives before it all of the burned products ofcombustion and leaves only pure air to be compressed on the inwardstroke. Unless the displacement of the pumps is greater than that of theworking pistons the cylinders will not be fully scavenged and one of thematerial features of advantage of my engine will be lost.

Driven by the crank shaft or other suit able source of power is atwo-stage air compressor 25 of the reciprocating type. Air is compressedtherein to whatever pressure it is desired to use in forcing air andfuel (usually a relatively heavy oil) into the working cylinders. Thecompressor discharges into a receiver 26 through a check valve 27located in the pipe 28. Air from the receiver is conveyed-to the inletvalve 29 by the pipe 30.

35 indlcates an upright shaft thatis driven from the crank shaft byspiral gears 36. On this shaft is a speed governor 37, the weights ofwhich move the sliding collar 38 up and down. To the collar is connected7 a lever 39 that raises and lowers the sliding block 40 to change theefi'ective stroke of the fuel pumps. On the shaft 35 is also aneccentric 41 or other means for oscillating the lever 42. 2 I

43 indicates a bell-crank lever actuated by the lever 42 and block 40for reciprocating the plungers of the fuel pump 44. The plungers areforced in one direction by springs and in the opposite direction by thelever. Each plunger serves one pair of working cylinders.

45 indicates a horizontal shaft driven by gearing from the shaft 35. Itis employed to open the valves 29 that admit fuel and air economy ofoperation.

under pressure to the conduit 22- and the working cylinders. On theshaft 45 are cams 46 that engage the rollers on the bell crank levers47, one such lever being provided for eachtwo working cylinders. Theright end of this lever engages the stem of the valve 29, Fig. l, andraises it against the pressure of the air from the reservoir 26. Thisvalve only remains open for a very short time. For example it may openwhen the crank is three degrees in advance of its dead center and closeafter it has moved seven degrees Owinggto the high compression .used inmy engine, as is the case with this type of engine generally, the fuelstarts to burn just as soon as it passes the admission valve 29,-therehy obviating the necessity of special sparking or ignition devices.

I have described only one pair of working and pump cylinders and theirpistons since the other pairs are similar in construction. The pistonsof the several pairs are of .course connected to the crank shaft in amanner to balance the thrusts as far as possible.

I may use any suitable form of water 'jacketing for cooling thecylinders.

By arranging the ports asv described and using the pistons as valves Iavoid the use. of puppet and other valves which are a great source oftrouble and which are difiicult to keep tight. Another and importantfeature is that my arrangement permits of operating the engine at anydesired high speed and the ports will always be opened and closed at theproper times. By using-one set of exhaust ports for two workingcylinders I avoid complications and also insure the com-- pletescavenging of the cylinders with an ex: cess of pure air over thatnecessary to fill the cylinder spaces. This latter feature is a mostimportant one as it directly affects the In accordance with patentstatutes, I have described the principle of operation of my inventiontogether with the apparatus which I now consider to represent the bestembodiment thereof; but I desire to have it understood that theapparatus shown is only illustrative, and that the invention can becarried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. In an engine of the character described,

' the combination of a pair of working cylinders, pistons that compressair in one end of said cylinders to a temperature above the ignitingtemperature of the fuel, a crank shaft connected with the pistons, aconduit connectingthe cylinders at their compression ends, exhaust portsfor one of the workthe provisions of the ing cylinders, a pair of airpumps, the pistons of. which have greater displacement than the workingpistons, means for conveying the air from both pumps to the otherworking cylinder, said air flowing through the cylindersand theirconnecting conduit serially and driving out the burned products ofcombustion, and a means including air under pressurefor injecting fuelinto the conduit connecting the cylinders wherein it is ignited by thehigh temperature air compressed by the workingpistons.

2. In an engineo "the character described, the combination of a pair ofworking cylinders and their pistons, a crank shaft connected to thepistons; a conduit connecting the cylinders, exhaust ports for one ofsaid cylinders only which are controlled by the working piston therein,air-admitting ports for the other working cylinder which are cont-rolledby the piston therein, a fresh air pump whose piston displacement ismaterially greater than that of the working pistons, a conduit conveyingair from the pump to the said air ports, the air from said ports flowingserially through the cylinders and conduit and escaping through theexhaust ports, a fuel supply, and an air compressor for forcing fuel andair into the cylinder spaces of both of the working cylinders againstthe compression produced by the working pistons.

3. In an engine of the character described, the combination of a pair ofworking cylinders, pistons in the cylinders that compress air in theends thereof, a crank shaft connected to the pistons, a conduitconnecting the compression spaces of the cylinders, an air pump having apiston displacement greater than that of the working pistons, a receiverconnected thereto having a cubical capacity substantially equal to thedisplacemcnt of the pump, air-admittirg ports in one of said cylindersthat communicate with the receiver and are controlled by the piston,exhaust orts in the other cylinder which are contro led by its piston,and means including air under pressure for injecting fuel into saidconduit where it is ignited by the high temperature air forced into itfrom both working cylinde s.

4. In an engine of the character described, t e combination of a pair ofworking cyliners and their pistons, a crank shaft for the pistons, aconduit connecting the cylinders attheir compression ends, an air pumphaving a piston displacement greater than that of the working pistons, areceiver connected thereto, air-admitting ports in one of said cylindersthat communicate with the receiver and are controlled by a' workingpiston, exhaust ports in the other cylinder which are controlled by itspiston, a staged air compressor, and a receiver that receivesair fromthe compressor and forces fuel intothe conduit where it is ignited bythe high temperature air forced into it from the cylinders by theworking pistons.

In witness whereof, I have hereunto set my hand this 22d day of June,1911.

HERMANN LEMP. Witnesses:

JOHN A. MoMANUs, J12, FRANK Gr. HATTIE.

